Electric heater for liquids



Feb. 27, 1923. 1,446,807

J. F. MERCER ELECTRIC HEATER FOR LIQUIDS Filed Nov. 29, 1921Ksheets-sheet; l

WITNESSES Feb. 27, 1923.

1,446,807 J. F. MERCER ELECTRIC HEATER FOR LIQUIDS Filed Nov 29, 1921 2sheets-sheet 2 Patented Feb. 27, 1923.

UNITED STATES PATENT OFFICE.

JOHN F. MERCER, OI GLOBE, ARIZONA, ASSIGNOB OI ONE-HALF TO WILLIAM W.BROOKNER, OF GLOBE, ARIZONA.

ELECTRIC HEATER FOR LIQUIDS.

Application filed November 29. 1921. Serial No. 518,529.

To all whom it may concern.

Be it known that I, JOHN F. MERCER, a citizen of the United States, anda resident of Globe, in the county of Gila and State of Arizona, haveinvented certain new and useful Improvements in Electric Heat ers forLiquids, of which the following is a specification.

This invention relates to an electric heater for liquids.

Among the objects of the invention is to provide a heater of thecharacter mentioned which is compact in construction and which has anexceedingly high heating capacity at a low consumption of current.

Other objects and objects relating to details of construction,combination and ar rangement of parts will hereinafter appear in thedetailed description to follow.

The invention is illustrated by way of example in the accompanyingdrawings, in which Figure 1 is a central vertical sectional view of theheater when fully assembled and connected with a liquid supply.

Figure 2 is a perspective view of the heat exchange unit;

Figure 3 is an enlarged detail view showing the manner in which theheating coils are supported and insulated and also showing theconnection thereof with a suitable source of current supply.

Figure 4 is a view similar to Figure 1 but showing a different form ofheating element.

Figure 5 is an enlarged perspective view illustrating the positioning ofthe heatlng element as used in Figure 4 between the different heattransferring casings.

Figure 6 is a perspectlve view of one of the heating elements.

Figure 7 is a fragmentary elevation lllus tra-ting the manner ofinsulating the heating elements from the casings of the heat exchangingcasings.

Referring to the drawlngs more art1 cularly, A indicates generally acylindrical casing in which there is enclosed the heat exchange unitgenerally indicated 10 the reference character B. The heat exc ange unitB more particularly consists in a pair of circular plate or head members10 between which there extends a'plurality of elongated casings 11, eachof which is rectangular in cross section a'n d serves as a passage forconductin a liquid through the heater. The ends of t e casing 11 areopen,

as shown, and sealed to prevent any li uid fitted an auxiliary head orcap 12 which is adapted to form a chamber '13 at each end of the heatexchange unit B. Also each ea or auxillary head 12 is formed with anippl 14 by which the same may be connected with a liquid supply asshown.

The casings 11 in the present instance are four in number and betweenadjacent pairs there is interposed three sheets of mica, these sheets ofmica are grouped as in Figure 3 and each generally indicated by thereference numeral 15. As shown each of the sheets of mica 15 correspondsin width and length to one side of a casing 11. The sheets of mica ofcourse may be replaced by other suitable insulating material, ifdesired, and preferably the outside sheets of each group are secured insome suitable manner to the adjacent wall of the associated casing 11.The middle sheet 16 of each group is for the purpose of supporting theheating coil. In this instance a resistance wire 17 is wound about eachmiddle sheet 16, and the wires are connected through the wires 18 and 19to one sideof the battery 20 and one terminal tion that the operation ofthe present invention is clearly apparent without a detailed descriptionthereof. Also it is believed that the advantages of the invention may beobvious. An important feature is the manner in which the resistancewires are disposed with relation to -the heat exchange unit B. By thisarrangement a high heating capacity of a small unit maybe obtained witha very low consumption of current.

Referring to Figures 4 to 7 inclusive, A indicates the housing or casingfor the-heat-v ing unit which is cylindrical in form similar to thatshown at A in Figure 1 and which has fitted in each end a head 28 and a.cap

29 each cap being providedwith a pipe 30 .which is adapted tocommunicate with the the casings 11 constituting the heat exchangingunit B shown specifically in Figure 2. The casings 32 are positionedbetween the heads 28 and each casing extending through the heads 28 sovthat the ends thereof communicate with the chambers 31. Also it may bementioned that the heads 28 may be formed with the casings 32 if sodesired. lin either instance the heads 28 are properly slotted about theends of-the casings 32 so that a liquid may not enter within the casingA.

In the present instance each heating element, one of which is shown inFigure 6,

consists in a sheeting 33 which may be made of material adapted to oflera higher resistance to the flow of electric current such as nichrome orthe like and each end has fitted thereon a bar 34 which is preferablymade of copper or other metal having good conductivity to the flow-ofelectric current.

As shown in Figure 5 one of the resistance elements is positionedbetween each adjacent air of casings 32 and adjacent the ends or thecasing 32 there are provided suitable transverse slots or grooves 35which are adapted for receiving the conductor bars 34 on the ends of theresistance sheets 33 also the resistance sheets 33 are properlyinsulated from the-sides of'the casings 32 by a sheet of mica as at 36(Figure 7 and likewise the bars 34 are insulated by mica strips or thelike, 37. An additional strip of mica or other insulating material 38may be used to further insulate the bars'34 from the casings '32. Y Y

- The resisting elements between the easings heretofore described arepreferably connected in series with each other which is accomplished bythe wires 38 in a manner which is obvious. ings 33 have their'upper barsconnected to the wires 39 and 40, said wires in turn being connected tothe binding post 4.1 and 42, respectively, and from the binding posts 41and 4:2 suitable wires may be shown to connect the heating unit with asuitable source of electric supply. Also if desired suitable resistancemay be inserted in the circuit supplying the electric heating unit asillustrated in Figure 3 of the drawings.

It is thought that the operation of the unit shown in Figures 4 to 7 ofthe drawings and described is entirely clear and it may be here remarkedthat the purpose .of the singular construction of heating elements is toThe two outermost sheet-- anse? provide a large heat radiating surfaceand .thereby afford a highly efiicient heating unit.

It also may be remarked that this particular unit has the sameadvantages as set out in the Figures 1, 2, and 3 inclusive, that is itofi'ersa large service for transmitting the heat from the heatingelements to the liquid to be heated through the use of a number ofcasings 32.

I claim:

1. An electric heater of the character described, comprising" aplurality of elongated casings disposed in parallel relation to eachother and each adapted to permit the passage of a liquid therethrough, aresistance element interposed betweenadjacent pairs of the casings, andmeans for connecting the resistance elements to a supply of electriccurrent.

2. An electric heater of the character described, comprising a pluralityof elongated casings which are square in cross section and disposed inparallel relation to each other and having their adjacent sides in closeproximity, a resistance element consisting in a sheeting of metal havinga high resistance to the flow of an electric current interposed betweeneach of the adjacent pairs of said casings, and means whereby saidresistance elements may be connected with a source of electric currentsupply.

3. An electric heater'of the character described comprising a pluralityof elongated casings which are rectangular in cross section, a circularhead connecting the similar ends of said casings, a cylindrical casingwithin which said first named casings are disposed, said circular headsbeing adapted to form a closure for the ends of said cylinsistanceelement interposed between each of the adjacent pairs of said casings,insulating means for resistance elements, and means whereby saidresistance elements may be connected with a source of electric current.

4. An electric heater of the character described comprising a heatexchange unit consisting in a plurality of elongated casings disposedparallel to each other and having their adjacent sides in closeproximity, a head for holding the similar ends of said casings inproper'spaced relation, means for circulating a liquid therethrough ineach of said casings, a resistanceooil interposed between each oftheadjacent pairs of said casings, and means for connecting saidresistaince coils to a source of electric current sup- P .V-

5. An electric heater of the character described, comprising a heatexchange unit consisting in a plurality of elongated casings disposedparallel to each other and having their adjacent sides in closeproximity, a head. for holding the similar ends of said casings inproper spaced relation, means for circulating a liquid through each ofsaid casings, a sheet of insulating material interposed between adjacentpairs of said casings, a coil wound upon said insulating sheet, andmeans whereby said coils may be connected with asource of electriccurrent supply.

6. An electric heater of the character de scribed, comprising a heatexchange unit consisting in a plurality of elongated casings disposedparallel to each other and having their adjacent sides in closeproximity, a head for holding the similar ends of said casings in properspaced relation, means for circulating a liquid through each of saidcasings, a sheet of insulating material interposed between each ofadjacent pairs of said casings, said sheet corresponding in dimensionsto one side of the casing, a resistance wire wound about said insulatingsheet longitudinally thereof, and means for connecting said resistancewires to a source of electric current supply.

7. An electric heater of the character described, comprising a heatexchange unit consisting in a plurality of elongated casings disposedparallel to each other and having their adjacent sides in closeproximity, a head for holding the similar ends of said casings inproperspaced relation, means for circulating a liquid through each ofsaid casings, a sheet of insulating material interposed between each ofthe adjacent pairs of said casings corresponding in dimensions to a sideof the casings, a resistance coil wound about each of said insulatingsheets longitudinally thereof, an insulating sheet disposed upon eachside of each of the insulating sheets carrying the resistance wires, andmeans whereby the resistance wires may be connected to a source ofelectric current supply.

8. An electric heater, comprising a plurality of casings arranged inclose proximity with each other, and a resistance element interposedbetween each adjacent pair of casings.

9. An electric heater, comprising a plurality of casings, each adaptedto retain a liquid and being arranged in close proximity with respect toeach other, and a plurality of resistance elements associated with saidcasings whereby a relatively large surface of the casings will beexposed to the resistance elements for the purpose described.

10. An electric heater, comprising a plurality of casings, each adaptedto retain a liquid and being arranged in close proximity with respect toeach other, a plurality of resistance elements associated wlth saidcasings whereby a relatively large surface of the casings will beexposed to resistance elements for the purpose described, and insulatingmeans for supporting said resistance elements.

11. An electric heater, comprising a plurality of casings arranged inclose proximity with each other, a resistance element interposed betweeneach adjacent pair of casings, and heat insulating means surroundingsaid casin gs JOHN F. MERCER.

